2020/04/23 by Gaurav Pande, Jyun-Yan Siao, Wei-Liang Chen +7 · 1 citation
Physics and Astronomy · #physics.app-ph #cond-mat.mes-hall
paper · pdf · doi:10.1021/acsami.0c01025
published as ACS Appl. Mater. Interfaces 12, 16, 18667-18673 (2020) · This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Applied Materials and Interfaces \{copyright} American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://pubs.acs.org/doi/abs/10.1021/acsami.0c01025
arxiv created 2020/04/23 · arxiv updated 2020/04/24
To explore the potential of field-effect transistors (FETs) based on monolayers of the two-dimensional semiconducting channel(SC) for spintronics, the two most important issues are to ensure the formation of variable low resistive tunnel ferromagnetic contacts(FC), and to preserve intrinsic properties of the SC during fabrication. Large Schottky barriers lead to the formation of high resistive contacts and methods adopted to control the barriers often alter the intrinsic properties of the SC. This work aims at addressing both issues in fully encapsulated monolayer WSe2 FETs by using bi-layer h-BN as a tunnel barrier at the FC/SC interface. We investigate the electrical transport in monolayer WSe2 FETs with current-in-plane geometry that yields hole mobilities ∼ 38.3 cm2V-1s-1 at 240 K and On/Off ratios of the order of 107, limited by the contact regions. We have achieved ultralow effective Schottky barrier (∼ 5.34 meV) with encapsulated tunneling device as opposed to a non-encapsulated device in which the barrier heights are considerably higher. These observations provide an insight into the electrical behavior of the FC/h-BN/SC/h-BN heterostructures and such control over the barrier heights opens up the possibilities for WSe2-based spintronic devices.